Rainbow Electronics MAX2104 User Manual
General description, Applications, Features
General Description
The MAX2104 low-cost direct-conversion tuner IC is
designed for use in digital direct-broadcast satellite
(DBS) television set-top box units. Its direct-conversion
architecture reduces system cost compared to devices
with IF-based architectures. The MAX2104 directly con-
verts L-band signals to baseband signals using a
broadband I/Q downconverter. The operating frequency
range extends from 925MHz to 2175MHz.
The IC includes an LNA gain control, I and Q downcon-
verting mixers, lowpass filters with gain control and fre-
quency control, a local oscillator (LO) buffer with a 90°
quadrature network, and a charge-pump based PLL for
frequency control. The MAX2104 also has an on-chip
LO, requiring only an external varactor-tuned LC tank
for operation. The output of the LO drives the internal
quadrature generator and dual modulus prescaler. An
on-chip crystal amplifier drives a reference divider as
well as a buffer amplifier to drive off-chip circuitry. The
MAX2104 is offered in a 48-pin TQFP-EP package.
Applications
DirecTV, PrimeStar, EchoStar DBS Tuners
DVB-Compliant DBS Tuners
Broadband Systems
LMDS
Features
♦ Low-Cost Architecture
♦ Operates from Single 5V Supply
♦ 925MHz to 2175MHz Input Frequency Range
♦ On-Chip Quadrature Generator, Dual-Modulus
Prescaler (/32, /33)
♦ On-Chip Crystal Amplifier
♦ PLL Mixer with Gain-Controlled Charge Pump
♦ Input Levels: -25dBm to -65dBm per Carrier
♦ Over 40dB Gain Control Range
♦ Noise Figure = 11.5dB; IIP3 = 7dBm (at 1550MHz)
♦ Automatic Baseband Offset Correction
♦ Loopthrough Replaces External Splitter
♦ Crystal Output Buffer
MAX2104
Direct-Conversion Tuner IC for
Digital DBS Applications
________________________________________________________________ Maxim Integrated Products
1
PLLIN-
PLLIN+
MOD-
MOD+
GND
IOUT+
IOUT-
V
CC
QOUT+
QOUT-
FDOUB
FLCLK
V
CC
CFLT
XTL-
XTL+
GND
V
CC
RFIN-
RFIN+
GND
GND
QDC-
QDC+
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
IDC-
IDC+
GND
GND
RFOUT
CPG1
V
CC
XTLOUT
CPG2
GC1
GC2
INSEL
CP
FB
GND
V
CC
TANK+
VRLO
TANK-
GND
GND
V
CC
PSOUT-
PSOUT+
TQFP
MAX2104
TOP VIEW
PART
MAX2104CCM*
0°C to +70°C
TEMP RANGE
PIN-PACKAGE
48 TQFP-EP
19-1431; Rev 3; 12/01
*Contact factory for availability.
Functional Diagram appears at end of data sheet.
Pin Configuration
Ordering Information
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.